Image display apparatus and correction method of image signal

ABSTRACT

An image display apparatus including a plurality of pixels, a drive circuit for outputting drive signals for driving the pixels, and a correction circuit for correcting an input signal corresponding to a predetermined pixel with a correction value to output a corrected input signal to a side of the drive circuit, wherein the apparatus adopts as the correction value a value reflecting drive states of pixels located in the neighborhood of the predetermined pixel, the value being one having received an adjustment according to a nonlinear characteristic between a value of the input signal and a gray-level display of the pixel on the basis of the value of the input signal corresponding to the predetermined pixel.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image display apparatus and acorrection method of a drive signal, and more particularly the presentinvention is suitable to be applied to an image display apparatus inwhich luminous bodies are made to emit light by energy rays.

2. Related Background Art

Conventionally, various kinds of image display apparatus are known. Asimage display apparatus which obtain light emission by the radiation ofenergy rays to luminous bodies, there are an image display apparatususing electron beams as the energy rays and a plasma display usingultraviolet rays as the energy rays.

As image display apparatus using electron-emitting devices beingelectron ray sources, for example, the following configurations areknown: the configuration using the so-called spindt typeelectron-emitting devices including cone-shaped electrodes and gateelectrodes located in the neighborhood of the electrodes, theconfiguration using surface conduction electron-emitting devices as theelectron-emitting devices, the configuration using carbon nanotubes asthe electron-emitting devices, and the like. As examples of imagedisplay apparatus using such electron-emitting devices, ones disclosedin Japanese Patent Application Laid-Open Nos. H11-250840 and H11-250839can be cited.

Moreover, the plasma displays using plasma generating devices (orcouples of electrodes for generating plasma) have been put on the marketalready. Furthermore, also the configuration using the plasma generatingdevices as addresses has been known, and the configuration of such aplasma address display is disclosed in, for example, Japanese PatentApplication Laid-Open No. 2001-13482. In the example disclosed in theJapanese Patent Application Laid-Open No. 2001-13482, there is discloseda method in which the deterioration of an image quality owing tointerference between image data of the plasma address display issuppressed by a correction in consideration of the data of pixelscausing the interference.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an image displayapparatus and a correction method of a drive signal, both capable ofrealizing a good image quality.

A first invention according to the present application is an imagedisplay apparatus, including:

a plurality of pixels;

a drive circuit for outputting drive signals for driving the pixels; and

a correction circuit for correcting an input signal corresponding to apredetermined pixel with a correction value to output a corrected inputsignal to a side of the drive circuit,

wherein the correction value is a value reflecting drive states ofpixels located in the neighborhood of the predetermined pixel, the valuebeing one having received an adjustment according to a nonlinearcharacteristic between a value of the input signal and a gray-leveldisplayed of the pixel on the basis of the value of the input signalcorresponding to the predetermined pixel.

As a configuration for performing the adjustment on the basis of thevalue of the input signal corresponding to the predetermined pixel, aconfiguration for performing the adjustment by directly using the valueof the input signal directly corresponding to the predetermined pixelcan be suitably adopted. The following configuration can be alsoadopted: a configuration for performing the adjustment by using a valueobtained by adding or subtracting a very small value to or from thevalue of the input signal, or a value obtained by multiplying the valueof the input signal by a gain in the neighborhood of 1 (the value is notthe value of the input signal itself corresponding to the predeterminedpixel, but a value available as a value equivalent to the value of theinput signal corresponding to the predetermined pixel), namely aconfiguration for performing the adjustment indirectly based on thevalue of the input signal corresponding to the predetermined pixel.Furthermore, the following configuration can be also adopted: aconfiguration for performing the adjustment by directly or indirectlyusing, as described above, the values of the input signals directlycorresponding to the pixels located in the neighborhood of thepredetermined pixel as the value of the input signal corresponding tothe predetermined pixel by utilizing the fact that input signalscorresponding to respective plural pixels located in the neighborhoodfrequently have values near to one another. Incidentally, in thisinvention, correction values which have been described above or will bedescribed more concretely in the following are adopted, but thecorrection values noted here may further include necessary conditionsfor performing corrections for other objects. Moreover, a configurationfor performing other corrections also by using other correction valueswith a correction circuit or other circuits is not excluded.

Moreover, a second invention according to the present invention is animage display apparatus, including:

a plurality of pixels, each including a luminous body and a device forexciting the luminous body;

a drive circuit for outputting drive signals for driving the devices;and

a correction circuit provided at a preceding stage of the drive circuitfor correcting an input signal corresponding to a predetermined pixelwith a correction value to output a corrected input signal to a side ofthe drive circuit,

wherein the correction value is a value corresponding to a value havingreceived an adjustment of an evaluation value according to a nonlinearcharacteristic between a value of the input signal and a gray-leveldisplayed of the pixel on the basis of the value of the input signalcorresponding to the predetermined pixel, the evaluation valuecorresponding to an amount of energy rays entering the luminous body ofthe predetermined pixel, the energy rays generated by drives of thedevices corresponding to pixels located in the neighborhood of thepredetermined pixel.

That the correction value is the value corresponding to the value havingreceived the adjustment of the evaluation value on the basis of thevalue of the input signal includes a case where the correction value isa value having received the adjustment of the evaluation value on thebasis of the value of the input signal itself (including the case of avalue having received the adjustment with a value having a correlationwith the value of the input signal (such as the values of the inputsignals corresponding to the pixels in the neighborhood of the pixelcorresponding to the input signal), and/or also including the case of avalue also adjusted by a value other than the value of the inputsignal), a case where the correction value is a value obtained byutilizing the value having received the adjustment of the evaluationvalue (such as the value obtained by adjusting the evaluation value onlywith the value of the input signal and the value determined by othervalues), and a case where the correction value is a value equivalent tothe value having received the adjustment of the evaluation value on thebasis of the value of the input signal which adjusted value is obtainedas a result of another method.

Now, there can be suitably adopted a configuration in which theevaluation value is a value corresponding to an amount of energy raysentering the luminous body of the predetermined pixel, the energy raysgenerated by drives of the devices corresponding to pixels driven attiming different from that of the predetermined pixel among the pixelslocated in the neighborhood of the predetermined pixel.

Moreover, there can be suitably adopted a configuration in which theapparatus corrects the input signal corresponding to the predeterminedpixel with the correction value so that a gray-level displayed obtainedby a corrected input signal is smaller than a gray-level displayedobtained by a not corrected input signal.

Moreover, there can be suitably adopted a configuration in which theapparatus further includes:

shielding members for suppressing incidence of energy rays generated bydrives of a part of the devices into luminous bodies neighboringluminous bodies corresponding to the part of the devices,

wherein the evaluation value is a value corresponding to energy raysentering the luminous body of the predetermined pixel, the energy raysgenerated by drives of the devices corresponding to the pixels locatedin the neighborhood of the predetermined pixel, the energy rays enteringthe luminous body of the predetermined pixel without being suppressed bythe shielding members.

A third invention of the present invention is an image displayapparatus, including:

a plurality of pixels, each including a luminous body and a device forexciting the luminous body;

a drive circuit for outputting drive signals for driving the devices;

shielding members for suppressing incidence of energy rays generated bydrives of a part of the devices into luminous bodies neighboringluminous bodies corresponding to the part of the devices; and

a correction circuit provided at a preceding stage of the drive circuitfor correcting an input signal corresponding to a predetermined pixelwith a correction value to output a corrected input signal to a side ofthe drive circuit,

wherein the correction value is a value corresponding to a value havingreceived an adjustment of an evaluation value according to a nonlinearcharacteristic between a value of the input signal and a gray-leveldisplayed of the pixel on the basis of the value of the input signalcorresponding to the predetermined pixel, the evaluation valuecorresponding to an amount of energy rays generated by drives of thedevices corresponding to pixels located in the neighborhood of thepredetermined pixel with the incidence of the energy rays into theluminous body of the predetermined pixel being suppressed.

For the invention, there can be suitably adopted a configuration inwhich the evaluation value is a value corresponding to an amount ofenergy rays generated by drives of the devices corresponding to pixelsdriven at timing different from that of the predetermined pixel amongthe pixels located in the neighborhood of the predetermined pixel withthe incidence of the energy rays into the luminous body of thepredetermined pixel being suppressed by the shielding members, and aconfiguration in which the apparatus corrects the input signalcorresponding to the predetermined pixel with the correction value sothat a gray-level displayed obtained by a corrected input signal islarger than a gray-level displayed obtained by a not corrected inputsignal.

Moreover, in each invention, there can be a configuration in which thecorrection value is a value corresponding to a value obtained bydividing the evaluation value by a gradient of a characteristic curve inthe neighborhood of the value of the input signal corresponding to thepredetermined pixel, the characteristic curve indicating a nonlinearcharacteristic between the value of the input signal and the gray-leveldisplayed of the pixel.

Moreover, the following configuration is also included as the inventionrelated to the present application. That is to say, the configuration isan image display apparatus, including:

a plurality of pixels;

a circuit for calculating a value of evaluation of an amount of energyrays entering a luminous body of a predetermined pixel, the energy raysgenerated by drives pixels located in the neighborhood of thepredetermined pixel;

an adjustment circuit for adjusting the value of the evaluation on thebasis of a value of an input signal according to a nonlinearcharacteristic between the value of the input signal and a gray-leveldisplayed of the pixel;

a circuit for correcting the input signal on the basis of an adjustedvalue; and

a drive circuit for outputting a drive signal for driving the pixel onthe basis of a corrected signal.

Moreover, the following configuration is also included as the inventionrelated to the present application. That is to say, the configuration isan image display apparatus, including:

a plurality of pixels;

shielding members for suppressing incidence of energy rays generated bydrives of a part of the plurality of pixels into luminous bodies ofpixels neighboring the pixel;

a circuit for calculating an evaluation value corresponding to an amountof energy rays generated by drives pixels located in the neighborhood ofa predetermined pixel with incidence of the energy rays into theluminous body of the predetermined pixel being suppressed by theshielding members;

an adjustment circuit for adjusting the evaluation value on the basis ofa value of an input signal according to a nonlinear characteristicbetween the value of the input signal and a gray-level displayed of thepixel;

a circuit for correcting the input signal on the basis of an adjustedvalue; and

a drive circuit for outputting a drive signal for driving the pixel onthe basis of a corrected signal.

Moreover, as the invention pertaining to the present application, alsothe following configuration is included. That is to say, theconfiguration is a correction method of an image signal, including thesteps of:

calculating a value reflecting drive states of pixels located in theneighborhood of a predetermined pixel;

adjusting the calculated value on the basis of a value of an inputsignal corresponding to the predetermined pixel according to a nonlinearcharacteristic between the value of the input signal and a gray-leveldisplayed of the pixel; and

correcting an image signal on the basis of the adjusted value.

According to the present invention, it is possible to provide an imageforming apparatus capable of realizing a good image quality.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph for illustrating the luminous characteristic of aphosphor used for an image display apparatus to which the presentinvention is applied;

FIG. 2 is a schematic diagram for illustrating a classification of ahalation area in the case where the line-sequential driving of an SEDaccording to a first embodiment of the present invention is performed;

FIG. 3 is a block diagram showing the configuration of a correctioncircuit of an image display apparatus according to the first embodimentof the present invention;

FIG. 4 is a block diagram showing a neighborhood data integratoraccording to the first embodiment of the present invention;

FIG. 5A is a schematic diagram showing a pixel arrangement in theperiphery of a watched pixel according to the first embodiment of thepresent invention, and FIG. 5B is a schematic diagram showing the valuesof coefficients a11 to a55;

FIG. 6 is a schematic diagram for illustrating a rise of a gray-leveldisplayed owing to the halation generated in the image display apparatusaccording to the first embodiment of the present invention;

FIG. 7 is a schematic diagram showing arrangements of pixels and spacersin the periphery of the watched pixel according to the first embodimentof the present invention;

FIGS. 8A, 8B, 8C and 8D are schematic diagrams showing the values of thecoefficients a11 to a55 according to the first embodiment of the presentinvention;

FIG. 9 is a block diagram showing the configuration of a correctioncircuit of an image display apparatus according to a third embodiment ofthe present invention;

FIG. 10 is a block diagram showing the details of a neighborhood dataintegrator according to the third embodiment of the present invention;

FIGS. 11A, 11B, 11C, 11D and 11E are schematic diagrams showing thevalues of coefficients a11 to a25, and a41 to a55 used for theneighborhood data integrator according to the third embodiment of thepresent invention;

FIG. 12 is a block diagram showing the configuration of a televisionapparatus using an image display apparatus according to an embodiment ofthe present invention; and

FIG. 13 is a perspective view showing the configuration of a displaypanel according to the embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present inventor focused his attention to an image display apparatusin which interference was generated between adjacent pixels, andascertained that the deterioration of an image quality (such as a shiftfrom aimed luminance and the unevenness of luminance in a screen) owingto the interference was produced. In particular, the present inventorexamined a technique especially suitable for improving the deteriorationof the image quality. First, the present inventor performed theexamination by using an image display apparatus adapted to useelectron-emitting devices and luminous bodies disposed with spaces fromthe electron-emitting devices as the image display apparatus in whichsuch interference between pixels is generated, and to radiate theelectrons emitted from the electron-emitting devices to the luminousbodies for making the luminous bodies emit light.

As for the image display apparatus, the present inventor repeatedexperiments for performing image display by opposing electron sourcesprovided with a plurality of electron-emitting devices to phosphorshaving different luminescent colors, and then the inventor found thatcolor reproducibility differed from desired states.

To give an actual example, it was found that, in case of using phosphorseach having one of the luminescent colors of blue, red and green toobtain light emission of blue by irradiating only the phosphors of bluewith electrons, not a light emission state of pure blue but a lightemission state including the other colors slightly, or a light emissionstate including light emissions of green and red concretely, wasobtained, namely a light emission state having not good chroma wasobtained.

Accordingly, the present inventor concentrated his energies on theresearches for the improvement of the image quality. As a result, theinventor ascertained that the cause of the lowering of the chroma foundin the conventional image display apparatus using the electron-emittingdevices was the generation of undesired light emission caused by theincidence of the electrons not only into a light emission areacorresponding to an electron-emitting device but also into the lightemission areas of different colors in the neighborhood of the lightemission area (including the light emission areas adjacent to the lightemission area) which electrons were ones emitted by theelectron-emitting device and entering the light emission areas directlyor after being reflected by a luminous body or the like corresponding tothe electron-emitting device, or ones generated by the electronsindirectly (secondary electrons). Accordingly, the present inventorfurther executed the examinations energetically. As a result, theinventor found a correction method capable of improving the influencesof the undesired light emission by signal processing.

In the following, the embodiments of the present invention will bedescribed with reference to the attached drawings. Incidentally, in allof the drawings of the following embodiments, the same or thecorresponding parts are denoted by the same reference marks. Moreover,in the following embodiments, the case of using a surface conductionelectron-emitting display (hereinafter briefly referred to as an SED)equipped with surface conduction electron-emitting devices aselectron-emitting devices will be described as an example.

First, the whole configuration of a display panel used in theembodiments is shown in FIG. 13.

As shown in FIG. 13, on a glass substrate 1201, which is an insulationsubstrate, there are formed scanning wiring 1203 being the wiring onwhich scanning signals are applied, modulation wiring 1204 being thewiring on which modulating signals based on signals having received thecorrections to be described in the following are applied, and surfaceconduction electron-emitting devices 1205 being devices. The scanningwiring 1203 and the modulation wiring 1204 are severally composed of aplurality of wires, and severally form matrix wiring for wiring devicesarranged in a matrix. A phosphor 1206 being a luminous body is formed ona glass substrate 1202 being an insulation substrate opposed to theglass substrate 1201. Each area of the phosphor 1206 opposed to eachsurface conduction electron-emitting device forms the luminous bodycorresponding to each surface conduction electron-emitting device.Between these luminous bodies black stripes 1207 are disposed.

Incidentally, a black matrix may be disposed in place of the blackstripes 1207. Moreover, a configuration in which each luminous body isnot comparted with such black stripes 1207 or a black matrix may be alsoadopted. Although the luminous bodies corresponding to respectivedevices may be formed to be a luminous body continuing to each otherwithout using the black stripe 1207 or the black matrix, each partcorresponding to each device is referred to as a luminous bodycorresponding to each device even in such a case.

Moreover, in the following embodiments, there will be shown the examplesof the application of the present invention to image display apparatuseach composed of a plurality of pixels severally including a luminousbody and a device for exciting the luminous body, and a drive circuitfor outputting drive signals for driving the devices.

First Embodiment

First, a description is given to a correction method of a drive signalfor reducing the lowering of chroma owing to halation (an undesiredlight emission in a predetermined pixel owing to the drive of (thedevices constituting) other pixels) in a surface conductionelectron-emitting display according to a first embodiment of the presentinvention. First, the principle of correction processing by the firstembodiment is described.

That is to say, in an SED, when the phosphor of a watched pixel being apredetermined pixel is irradiated by electrons, a light emission in theshape of a circle owing to the halation is generated around the watchedpixel. The circular area influenced by the halation is referred to as a“halation area” of the pixel. Conversely, it can be also consideredthat, when a pixel is lighted in the halation area of the watched pixel,the watched pixel is lighted as the halation by the reflection electronsfrom the pixel.

Thus, even if the watched pixel is intended to be displayed at a certaindegree of luminance, the luminance actually displayed becomes higherowing to the halation from surrounding pixels. Because a rise of theluminance owing to the halation is generated by almost the same degreein each of the colors of red (R), green (G) and blue (B), white resultsto be added to the original color of the watched pixel, and a fall inchroma is produced.

Accordingly, a correction method according to the first embodimentestimates a rise of the luminance of the watched pixel owing to thehalation of surrounding pixels, and corrects the drive data of thewatched pixel to deduct the amount of the rise previously. Consequently,the light emission owing to the halation from the surrounding pixels isadded when the display is performed actually, and thereby the desiredlight emission can be obtained to prevent the fall of the chroma. In thefollowing, the respect is described in detail.

That is to say, it is known that the intensity of the reflectionelectrons owing to the halation is a fixed ratio to the amount of theelectric charges irradiating the phosphor and is almost uniform in thecircular area in the SED. Moreover, the amount of the electric chargesirradiating the phosphor is in proportion to the drive data of a pixel.Consequently, it is possible to calculate the amount of the electroncharges entering a certain pixel which electrons are the reflectionelectrons from the pixels in the neighborhood of the pixel on the basisof the integrated data of the amount of the electron charges based onthe drive data of the pixels in the halation area of the pixel.

Incidentally, the present embodiment adopts the amount of the reflectionelectrons entering the luminous body of the predetermined pixel as avalue which reflects the drive states of the pixels located in theneighborhood of the predetermined pixel and is a value obtained byevaluating the amount of the incidence of the energy rays generated bythe driving of the devices corresponding to the pixels located in theneighborhood of the predetermined pixel into the luminous body of thepredetermined pixel. The reflection electrons have been generated by thedriving of the devices of the pixels in the neighborhood of thepredetermined pixel. But, the electrons entering the pixel directly fromthe devices of the other pixels and the secondary electrons produced bythe electrons may be considered.

If the calculation of the amount of electron charges becomes possible,the calculation of a rise of the luminance becomes possible on the basisof the relationship between the amount of the electron charges and theluminance. Incidentally, the matters considered in the presentembodiment are the luminous characteristics of the phosphors and thedrive method of the SED. FIG. 1 schematically shows the luminouscharacteristic of the phosphor used for the SED according to the firstembodiment. Incidentally, in FIG. 1, the dependence of the drive data(abscissa axis) of a pixel to the gray-level displayed (ordinate axis)of the phosphor is shown. Moreover, the gray-level displayed indicatesthe luminance obtained by integrating the light emission of a phosphorfor a frame period.

As shown in FIG. 1, the luminous characteristic of the phosphor is not alinear characteristic. The luminous characteristic has the tendency ofbeing saturated as the drive data becomes larger when the amount of theelectric charges to the phosphor increases. To put it concretely,provided that the luminous characteristic is expressed as a functionγ(x) of the drive data x, the gradient of the luminous characteristicwhen the drive data is X can be expressed by the differentialcoefficient γ′(X) at x=X in the derived function γ′(x) of the functionγ(x).

Consequently, provided that the gray-level displayed at the time whenthe drive data is X is denoted by L, a variation ΔL of the gray-leveldisplayed when the drive data has varied from X by ΔX is expressed bythe following expression (1).

ΔL→ΔX×γ′(X)  (1)

From the expression (1), it is deduced that, even if the variation ofthe drive data is the same, the variation of the gray-level displayeddiffers according to the magnitude of the original drive data.

Next, the drive method of the SED is described. FIG. 2 shows adisposition of five pixels in each of length and width around apredetermined pixel p33, which is set as a watched pixel. Incidentally,in FIG. 2, a pixel pnm (n, m: 1 to 5) denotes each pixel around thewatched pixel p33. Moreover, because the halation of the SED is acircle, the halation from the pixels existing in the areas A, B and Cshown in FIG. 2 influences the watched pixel p33.

In case of adopting a line-sequential driving as the drive method of theSED, pixels on one row are lighted at the same time during a horizontalsynchronization period. Then, the pixels on the other rows are put outduring the lighting of the pixels on the row. In the state shown in FIG.2, first, pixels p11 to p15 are lighted at the same time. After that,pixels p21 to p25, p31 to p35, p41 to p45 and p51 to p55 are severallylighted at the same time in order.

That is to say, during the pixels on one row are lighted, the pixels onthe other rows are not lighted. Consequently, the reflection electronsof the halation entering the watched pixel p33 are reflection electronsfrom the pixels in the area B which reflection electrons have beenradiated into the phosphor of the watched pixel at the same time whenthe watched pixel p33 is lighted. On the other hand, the reflectionelectrons of the halation from the pixels in the areas A and C areradiated into the phosphor of the watched pixel p33 when the watchedpixel p33 is not lighted.

That is to say, a rise ΔL1 of the gray-level displayed owing to thehalation from the areas A and C is expressed by the following expression(2) on the supposition that the magnitude of the drive datacorresponding to the amount of electric charges owing to the halation isQ1 (see FIG. 6).

ΔL1=Q1Δγ′(0)  (2)

On the other hand, as for the pixels in the area B, the reflectionelectrons are radiated into the watched pixel p33 at the same time asthe lighting of the watched pixel p33. Consequently, a rise ΔL2 of thegray-level displayed of the halation from the pixels in the area B isexpressed by the following expression (3) on the supposition that themagnitude of the drive data corresponding to the amount of electriccharges owing to the halation is Q2 (see FIG. 6).

ΔL2=Q2×γ′(X)  (3)

Consequently, the rise of the gray-level displayed owing to the halationis expressed by the following expression (4).

ΔL3=ΔL1+ΔL2  (4)

The drive data of the watched pixel p33 is corrected so as to deduct therise of the gray-level displayed. For the deduction, the rise of thegray-level displayed may be divided by the gradient of the luminouscharacteristic of the phosphor at the drive data X of the watched pixelp33. Provided that the correction amount of the drive data, or thecorrection value, is ΔX, the following expression (5) is true.

$\begin{matrix}{{\Delta \; X} = \frac{\Delta \; L\; 3}{\gamma^{\prime}(X)}} & (5)\end{matrix}$

Then, when the expressions (2) and (3) are applied to the expression(5), the following expression (6) is obtained.

$\begin{matrix}{{\Delta \; X} = {{Q\; 1 \times \frac{\gamma^{\prime}(0)}{\gamma^{\prime}(X)}} + {Q\; 2}}} & (6)\end{matrix}$

Now, as described above, the amount of the electron charges owing to thehalation at a certain pixel is an amount obtained by multiplying theamount of the electron charges radiated to the phosphor at the pixel bya fixed rate. Consequently, the magnitude of the drive datacorresponding to the amount of the electron charges of the halation atthe pixel linearly varies.

That is to say, the magnitude of the drive data corresponding to theamount of the electron charges of the halation is the magnitude obtainedby multiplying the drive data at the pixel by a fixed ratio. Hereupon,when the ratio is supposed to be a proportionality constant k and thesummation of the drive data in the areas A and C of FIG. 2 is supposedto be C1, the following expression (7) is true.

Q1=k×C1  (7)

Moreover, when the summation of the drive data in the area B of FIG. 2is supposed to be C2, the following expression (8) is true.

Q2=k×C2  (8)

Consequently, the expression (6) is changed to the following expression(9).

$\begin{matrix}{{\Delta \; X} = {{k \times C\; 1 \times \frac{\gamma^{\prime}(0)}{\gamma^{\prime}(X)}} + {k \times C\; 2}}} & (9)\end{matrix}$

Moreover, when the drive data after the correction by ΔX of the drivedata X is denoted by X′, the following expression (10) is introducedfrom the expression (9).

$\begin{matrix}{X^{\prime} = {{X - {\Delta \; X}} = {X - {k \times C\; 1 \times \frac{\gamma^{\prime}(0)}{\gamma^{\prime}(0)}} - {k \times C\; 2}}}} & (10)\end{matrix}$

By setting the drive data (drive signal) X′ to be a value expressed bythe expression (10), desired display luminance can be realized, and thedegradation of the chroma can be diminished.

(Correction Circuit)

Next, a correction circuit implementing the correction principledescribed above is described. FIG. 3 shows the configuration of thecorrection circuit of the image display apparatus according to the firstembodiment.

As shown in FIG. 3, the correction circuit according to the firstembodiment is composed of adders 6 and 7, coefficient arithmeticoperation units 8 and 9, look-up tables (LUTs) 10R, 10G and 10B, adders11R, 11G and 11B, multipliers 12R, 12G and 12B, adders 13R, 13G and 13B,limiters 14 and neighborhood data integrators 20.

The neighborhood data integrators 20 are composed of three circuitshaving the same configurations for R, G and B severally. Then, theneighborhood data integrators 20 are configured in order that the drivedata R1, G1 and B1 (input signals for respective colors) of respectivepixels of R, G and B before correction may be first input into therespectively corresponding neighborhood data integrators 20. A detailedconfiguration of the neighborhood data integrators 20 is shown in FIG.4.

(Neighborhood Data Integrators)

As shown in FIG. 4, the neighborhood data integrators 20 are severallycomposed of one-horizontal synchronization period (1H) delay circuits 1,one-pixel (1P) delay circuits 2, multipliers 3 for multiplying data bycoefficients, horizontal adders 4 for integrating data in horizontaldirections, and vertical adders 5 for integrating the data having beenadded in the horizontal directions in vertical directions.

Then, in the processing of the neighborhood data integrators 20, drivedata R1, G1 and B1 of each pixel of R, G and B before correction isinput into the neighborhood data integrators 20, respectively.Incidentally, because the neighborhood data integrators 20 for R, G andB severally have the same configuration, the neighborhood dataintegrator 20 for R is described in the first embodiment as arepresentative example.

First, the 1H delay circuits 1 are described. That is to say, the dataR1 having input into the neighborhood data integrator 20 according tothe first embodiment is delayed by each of the 1H delay circuits 1 byone horizontal scanning period (1H). In the following description, thesignal obtained by delaying the data R1 by the one horizontal scanningperiod (1H) is denoted as a signal R2, the signal obtained by delayingthe data R1 by the further one horizontal scanning period (1H) isdenoted as a signal R3, the signal obtained by delaying the data R1 bythe further one horizontal scanning period (1H) is denoted as a signalR4, and the signal obtained by delaying the data R1 by the further onehorizontal scanning period (1H) is denoted as a signal R5.

Image data is normally input from the row data on the upper side of thescreen. Consequently, the signal R2 is always the data displayed at arow upper by one to the row of the signal R1 in the screen. Similarly,the signal R3 is the data displayed at a row upper by one to the row ofthe signal R2, the signal R4 is the data displayed at a row upper by oneto the row of the signal R3, and the signal R5 is the data displayed ata row upper by one to the row of the signal R4.

Next, the 1P delay circuits 2 are described. The 1P delay circuits 2according to the first embodiment are circuits for severally delayingdata by one pixel in the horizontal direction.

To put it concretely, when the lowermost row 21 is exemplified, thesignal obtained by delaying the input signal R5 by one pixel is a signalR6. Image data is normally input from the data on the left side in thescreen. Consequently, the signal R6 is always the image data on the leftside of the signal R5 on the screen. Similarly, a signal R7 is the imagedata on the left side of the signal R6, a signal R8 is the image data onthe left side of the signal R7, and a signal R9 is the image data on theleft side of the signal R8. Incidentally, the lowermost row 21 isdescribed here, but similar processing is executed by the 1P delaycircuits 2 in any row in the neighborhood data integrator 20.

Moreover, it is supposed that the data (hereinafter referred to aswatched pixel data) of the central pixel (hereinafter referred to as awatched pixel) in the pixels on the left, right, top and bottom in theneighborhood data integrator 20 is R15. The watched pixel data R15 isthe data obtained by delaying the data of the signal R3 horizontally bytwo pixels. That is to say, the watched pixel data R15 is the data fordriving the pixel which has shifted by two pixels to the left side fromthe display pixel of the data R3, and the watched pixel data R15 is thedata for driving the pixel which has shifted by two pixels into lowerdirection from the display pixel of the data R7.

When the watched pixel data R15 is watched, the data in the inside ofthe neighborhood data integrator 20 is the data in a rectangle of fivepixels in length and width around the watched pixel as the center. Thatis to say, the neighborhood data integrator 20 is configured to be ableto process the data for five pixels in length and width around thewatched pixel data as the center.

Moreover, the range of the data processed by the neighborhood dataintegrator 20 is determined according to the range influenced by thehalation. In the SED according to the first embodiment, when electronsare radiated onto an arbitrary phosphor, a circular light emission owingto the halation is generated around the pixel to which the electrons areradiated. Consequently, when the diameter of the circular areainfluenced by the halation is for n pixels, it is needed to executeprocessing for n pixels in length and width. Incidentally, in the abovedescription, n is supposed to five. However, the value of n isdetermined on the basis of the diameter (range) of the circular areainfluenced by the halation. For example, when the range influenced bythe halation includes only the pixels adjoining to the watched pixel onthe left, right, top and bottom of the watched pixel, n may be set to bethree. As the value of n, various values can be adopted according to therange influenced by the halation.

Moreover, the diameter of the circular area influenced by the halationis uniquely determined on the basis of the space between the face plate,on which the phosphors are arranged, and the rear plate, on which theelectron sources are arranged. Consequently, when the space between theface plate and the rear plate has been known, the range of pixels towhich processing is executed can be uniquely determined.

(Multipliers)

Moreover, although the multipliers 3 are ordinarily ones each outputtingone signal generated by multiplying two inputs, the multipliers 3 aredrawn to be simplified by showing factors by which inputs are multipliedas shown in FIG. 4 in the first embodiment. That is to say, for example,the multiplier 3 to which the data R5 is input outputs an outputobtained by multiplying the data R5 by a coefficient a15. Moreover, theneighborhood data integrator 20 is configured in order that the data R6may be multiplied by a coefficient a14, that the data R7 may bemultiplied by a coefficient a13, that the data R8 may be multiplied by acoefficient a12, and that the data R9 may be multiplied by a coefficienta11. Although the processing of the multipliers 3 has been describedhere with regard to the lowermost row 21 of the neighborhood dataintegrator 20, similar processing is executed in any row of theneighborhood data integrator 20.

(Horizontal Adders)

Moreover, the horizontal adders 4 are ones for adding data for one row.In the first embodiment, four horizontal adders 4 are provided to eachrow. Furthermore, because these horizontal adders 4 exist for five rows,4×5=20 of horizontal adders are required as the horizontal adders 4 inthe neighborhood data integrator 20. Incidentally, the data input intothe horizontal adders 4 is the signals output from the multipliers 3described above, and it is the horizontal adders 4 that execute theaddition of the data output from the multipliers 3 for one row.

If the processing of the multipliers 3 and the horizontal adders 4 isexpressed by an expression by exemplifying, for example, the lowermostrow 21 of the neighborhood data integrator 20, the following expression(11) is obtained.

R10=R5a15+R6×a14+R7×a13+R8×a12+R9×a11  (11)

The operation processing expressed by the expression (11) is theprocessing at the lowermost row 21 of the neighborhood data integrator20. Then, the processing is similarly executed on any row in theneighborhood data integrator 20. Incidentally, the details of thecoefficients a11 to a55 will be described later.

The neighborhood data integrated in the horizontal directions in the waydescribed above is added in the vertical direction by the verticaladders 5 except the data of the row 22. Then, when it is supposed thatthe neighborhood data of each row output from the horizontal adders 4 isdenoted by R10 to R14, respectively, as shown in FIG. 4, an output valueR16 of the vertical adder 5 can be expressed by the following expression(12).

R16=R10+R11+R13+R14  (12)

The expression (12) shows the data obtained by integrating the productsof the multiplication of the image data driven at the timing differentfrom that of the watched pixel among the neighborhood data of thewatched pixel by the coefficients. On the other hand, the data R12 ofthe row 22 excepted from the calculation described above is obtained byintegrating the products of the multiplication of the pixel data drivenat the same timing as that of the watched pixel among the neighborhooddata of the watched pixel by the coefficients. Now, the coefficients a11to a55 of the neighborhood data integrator 20 are described.

FIG. 5A shows an arrangement of five pixels along the vertical directionand the horizontal direction around the watched pixel p33, which is thearea generating the halation to the watched pixel p33. Incidentally, inFIG. 5A, a reference mark pnm (n, m=1 to 5, p11 to p55) severallydenotes a pixel. Then, it is supposed that the coefficients by which thedata of the pixels p11 to p55 is multiplied are a11 to a55,respectively, at certain timing.

As shown in FIG. 5A, the halation area in which the halation isgenerated at the watched pixel (p33) is a circle in the SED according tothe first embodiment. The halation area to the watched pixel p33 isexhibited by a solid line 60. Then, for simplifying the coefficients a11to a55, as to the pixels located in the circular halation area, thesolid line 60 is approximated by a dotted line 61.

Moreover, in the first embodiment, the values of the coefficients a11 toa55 take either value of 0 and 1. Then, the coefficients of pixelscapable of causing the halation light emission of the watched pixel areseverally 1, and the other coefficients are severally 0. Moreover,because the pixels capable of causing the halation light emission of thewatched pixel are ones within the dotted line 61 shown in FIG. 5A, thecoefficients a11 to a55 are determined as shown in FIG. 5B.Incidentally, in FIG. 5B, an upper left position indicates thecoefficient a11, a lower right position indicates the coefficient a55,and the center position indicates the watched pixel a33. Moreover, adotted line indicates the range of an approximated halation areasimilarly to FIG. 5A.

Although the area of the pixels which can cause the halation lightemission to the watched pixel is supposed to be the area composed of 5×5pixels, the former area is not necessarily limited to the latter area.In the case where the area of the pixels capable of generating thehalation in the watched pixel is the area composed of 3×3 pixels, thecoefficients of the pixels on the left, right, top and bottom of thewatched pixel, namely a23, a32, a33, a34 and a43, may be set to be 1,and the coefficients of the other pixels may be set to be 0.Incidentally, in the case where the reflection electrons of the watchedpixel (p33) are not radiated onto the watched pixel itself, thecoefficient a33 corresponding to the watched pixel may be set to be 0.

Moreover, in the SED, the halation light emission is generated in acircular area around a bright spot. It is known that the intensity L1 ofthe halation light emission is almost uniform over the pixels in thecircular area. Consequently, all of the coefficients in the circulararea take the same value.

By setting the coefficients a11 to a55 in the way described above, thedata R16 shown in FIGS. 3 and 4 is an integrated value of the pixel datadriven at timing different from that of the watched pixel (p33) amongthe pixels generating the halation light emission at the watched pixel(p33). Moreover, the data R12 is an integrated value of the pixel datadriven at the same timing as that of the watched pixel (p33) among thepixels generating the halation light emission at the watched pixel(p33). Then, in the first embodiment, the data R16 and R12 are referredto as neighborhood data integrated values. Thus, by the neighborhooddata integrator 20, three signals of the watched pixel data R15 and theneighborhood data integrated values R12 and R16 are output.

In the way described above, the processing of the neighborhood dataintegrator 20 is executed. Incidentally, although the processing of R isexemplified to be described in the processing of the neighborhood dataintegrator 20 described above, similar processing is executed to G andB. That is to say, in the processing of G, when image data G1 is input,watched pixel data G15, and neighborhood data integrated values G12 andG16 are output. In the processing of B, when image data B1 is input,watched pixel data B15, and neighborhood data integrated values B12 andB16 are output.

Next, referring to FIG. 3, the processing of the subsequent stages ofthe neighborhood data integrators 20 is described. The neighborhood dataintegrated values R16, G16 and B16 output from the neighborhood dataintegrators 20 are added to one another by the adder 6. If the output ofthe adder 6 is denoted by a reference mark W1, the output W1 isexpressed by the following expression (13).

W1=R16+G16+B16  (13)

In the expression (13), W1 is the data obtained by integrating all ofthe data of R, G and B, each of which has been obtained by integratingthe products of the multiplication of the data driven at timingdifferent from that of the watched pixel (p33) among the data in theneighborhood of the watched pixel (p33) by the coefficients a11 to a15,a21 to a25, a41 to a45 and a51 to a55, respectively. That is to say, thedata W1 is the data corresponding to the drive data C1 in theexpressions (7), (9) and (10).

Moreover, the halation is a physical light emission caused by reflectionelectrons. Consequently, the halation itself is generated independent ofR, G and B. That is to say, in the image display apparatus, thereflection electrons of R make the watched pixels of G and B emit light.Similarly, also the reflection electrons of G and B make the watchedpixels of R and B, and R and G emit light, respectively. Consequently,for reducing the halation, it is necessary to subtract the halation dataof the other colors from the data of the watched pixel.

Accordingly, the coefficient arithmetic operation unit 8 is configuredin order that, after the coefficient arithmetic operation unit 8 hasmultiplied the inputted output data W1 by a predetermined coefficient,the coefficient arithmetic operation unit 8 may invert the sign of theproduct to output the inverted product. The coefficient of themultiplication is the ratio of the halation to the above-mentioned drivedata, namely the proportionality constant k similar to one in theexpression (10).

The value obtained by the multiplication of W1 by the predeterminedcoefficient corresponds to a value as a result of the evaluation of theamount of the incidence of the energy rays into the luminous body of thewatched pixel which energy rays have been generated by the drives of thedevices at the pixels driven at the timing different from that of thewatched pixel among the pixels located in the neighborhood of thewatched pixel. Consequently, output data W3 of the coefficientarithmetic operation unit 8 is expressed by the following expression(14).

W3=−k×W1  (14)

On the other hand, the data R12, G12 and B12 output from theneighborhood data integrators 20 are input into the adder 7 to be addedto one another. In the case where an output of the adder 7 is denoted bya reference mark W2, the output W2 is expressed by the followingexpression (15).

W2=R12+G12+B12  (15)

The above-mentioned output W2 is the data obtained by integrating all ofthe data of R, G and B, each of which has been obtained by integratingthe products of the multiplication of the data driven at the same timingas that of the watched pixel among the data in the neighborhood of thewatched pixel by the coefficients a31 to 35, respectively. That is tosay, the data W2 is the data corresponding to the drive data C2 in theexpressions (8) to (10).

Moreover, in the coefficient arithmetic operation unit 9, after themultiplication of the input data W2 by a predetermined coefficient, thesign of the multiplied data is inverted, and the product having theinverted sign is output. The coefficient is a proportionality constant ksimilarly to the case of the coefficient arithmetic operation unit 8.Consequently, output data W4 of the coefficient arithmetic operationunit 9 is expressed by the following expression (16).

W4=−k×W2  (16)

Moreover, the output W4 of the coefficient arithmetic operation unit 9is added to the data R15, G15 and B15 by the adders 11R, 11G and 11B,respectively, to be output as data R17, G17, and B17, respectively. Ifthe processing is expressed by an expression, the expression is thefollowing expression (17).

$\begin{matrix}\left. \begin{matrix}\begin{matrix}{{R\; 17} = {{{R\; 15} + {W\; 4}} = {{R\; 15} - {k \times W\; 2}}}} \\{{{G\; 17} - {G\; 15} + {W\; 4}} = {{G\; 15} - {k \times W\; 2}}}\end{matrix} \\{{B\; 17} = {{{B\; 15} + {W\; 4}} = {{B\; 15} - {k \times W\; 2}}}}\end{matrix} \right\} & (17)\end{matrix}$

The pieces of data R17, G17 and B17 are multiplied by the outputs ofLUTs 10R, 10G and 10 b in the multipliers 12R, 12G and 12B,respectively, and are output as data R18, G18 and B18, respectively.

If drive data of a pixel is denoted by X, the gray-level displayed of Rto the drive data X is denoted by γR(X), and the gradient of thegray-level displayed γR(X) to the drive data X is denoted by γR′(X),then the LUT 10R receives the input X, and outputs γR′ (0)/γR′ (X).Similarly, if the gray-level displayed of G to the drive data X isdenoted by γG(X), and the gradient of the gray-level displayed γG(X) tothe drive data X is denoted by γG′ (X), then the LUT 10G receives theinput X, and outputs γG′ (0)/γG′ (X). Moreover, if the gray-leveldisplayed of B to the drive data X is denoted by γB(X), and the gradientof the gray-level displayed γB(X) to the drive data X is denoted by γB′(X), then the LUT 10B receives the input X, and outputs γB′ (0)/γB′ (X)Consequently, the outputs R18, G18 and B18 of the multipliers 12R, 12Gand 12B are expressed by the following expression (18).

The value is one obtained by adjusting a value on the basis of the valueof the drive data being an input signal according to the nonlinearcharacteristic between the drive data being the input signal and thegray-level displayed. The value to be adjusted is obtained by evaluatingan amount of the incidence of the energy rays into the luminous body ofthe watched pixel. The incident energy rays have been generated by thedrives of the devices at the pixels driven at the timing different fromthat of the watched pixel among the pixels in the neighborhood of thewatched pixel.

$\begin{matrix}\left. \begin{matrix}\begin{matrix}{{R\; 18} = {{W\; 3 \times \frac{\gamma \; {R^{\prime}(0)}}{\gamma \; {R^{\prime}\left( {R\; 15} \right)}}} = {{- k} \times W\; 1 \times \frac{\gamma \; R^{\prime}(0)}{\gamma \; {R^{\prime}\left( {R\; 15} \right)}}}}} \\{{G\; 18} = {{W\; 3 \times \frac{\gamma \; {G^{\prime}(0)}}{\gamma \; {G^{\prime \;}\left( {G\; 15} \right)}}} = {{- k} \times W\; 1 \times \frac{\gamma \; {G^{\prime}(0)}}{\gamma \; {G^{\prime}\left( {G\; 15} \right)}}}}}\end{matrix} \\{{B\; 18} = {{W\; 3 \times \frac{\gamma \; {B^{\prime}(0)}}{\gamma \; {B^{\prime}\left( {B\; 15} \right)}}} = {{- k} \times W\; 1 \times \frac{\gamma \; {B^{\prime}(0)}}{\gamma \; {B^{\prime}\left( {B\; 15} \right)}}}}}\end{matrix} \right\} & (18)\end{matrix}$

Moreover, the data R17 and the data R18 are added to each other by theadder 13R. Similar processing is performed also for G and B, and therespective outputs R19, G19 and B19 of the adders 13R, 13G and 13B areexpressed by the following expressions.

$\begin{matrix}\left. \begin{matrix}\begin{matrix}{{R\; 19} = {{{R\; 17} + {R\; 18}} = {{R\; 15} - {k \times W\; 1 \times \frac{\gamma \; {R^{\prime}(0)}}{\gamma \; {R^{\prime}\left( {R\; 15} \right)}}} - {k \times W\; 2}}}} \\{{G\; 19} = {{{G\; 17} + {G\; 18}} = {{G\; 15} - {k \times W\; 1 \times \frac{\gamma \; {G^{\prime}(0)}}{{\gamma \; {G^{\prime}\left( {G\; 15} \right)}}\;}} - {k \times W\; 2}}}}\end{matrix} \\{{B\; 19} = {{{B\; 17} + {B\; 18}} = {{B\; 15} - {k \times W\; 1 \times \frac{\gamma \; {B^{\prime}(0)}}{\gamma \; {B^{\prime}\left( {B\; 15} \right)}}} - {k \times W\; 2}}}}\end{matrix} \right\} & (19)\end{matrix}$

In these expressions, the reference mark W1 corresponds to C1 in theexpression (10), and the reference mark W2 corresponds to C2 in theexpression (10). Thereby, the corrections corresponding to thecorrections shown in the expression (10) are performed, and the fall ofchroma can be reduced. Incidentally, the limiters 14 are limitercircuits provided for outputting 0 in the case where the operationresults of the adders 13R, 13G and 13B become negative.

As described above, in the image display apparatus according to thefirst embodiment, the correction circuits each for executing thecorrection of the input signal by subtracting a predetermined correctionvalue from an input signal corresponding to the device of a watchedpixel are provided at the preceding stages of the drive circuits in theimage display apparatus. Then, as the correction value, the imagedisplay apparatus adopts a value determined on the basis of a valueobtained by dividing an evaluation value by a differential coefficientin the neighborhood of an input signal corresponding to the watchedpixel in a gray-level displayed characteristic depending on an inputsignal. The evaluation value has been obtained by evaluating an increaseof the gray-level displayed of the watched pixel owing to the drives ofthe devices of the pixels located in an area where the halation aroundthe watched pixel is generated which devices are driven at the timingdifferent from that of the watched pixel. Thereby, the influences of thehalation in the halation area can be reduced by the correctionprocessing, and as a result, bad influences owing to the halation can beremoved. Consequently, the image display apparatus capable of obtaininga good light emission state can be obtained.

Incidentally, here, the influences to the gray-level displayed of thewatched pixel owing to the drives of the pixels (devices) driven at thesame timing as that of the watched pixel are evaluated to correct thedata corresponding to the watched pixel, and the influences to thegray-level displayed of the watched pixel owing to the drives of thepixels (devices) driven at the timing different from that of the watchedpixel are evaluated to correct the data corresponding to the watchedpixel. However, the data (the data to be corrected) corresponding to thewatched pixel is not necessarily to be the data constituting the sameframe as the frame of the corresponding data of the neighborhood pixelsused for the calculation of the correction values, and the correctionvalues calculated on the basis of the data of a certain frame can alsobe used for the correction of the data of another frame by utilizing thecorrelativity of data between neighborhood frames.

Second Embodiment

Next, an image display apparatus according to a second embodiment of thepresent invention is described. In the image display apparatus accordingto the second embodiment, spacers as shielding members for interceptingelectrons are provided differently from the first embodiment. Thespacers are severally a plate-like member arranged at the center betweena certain pixel row and the pixel row under the former pixel row. Then,a description is given to a case where correction circuits are providedat the preceding stages of the drive circuits of the image displayapparatus provided with the spacers and the correction processing of theneighborhood of the spacers is executed differently from the firstembodiment. Incidentally, because the configurations and correctionmethods other than those to be described in the following are the sameas those in the first embodiment (see FIGS. 3 and 4), the descriptionsof the configurations and the correction methods are omitted.

That is to say, spacers as support members of the atmospheric pressureare normally provided in a SED. But, the spacers exist between luminousbodies and also function as shielding members for intercepting theelectrons which are to be reflected by the luminous bodies on one sideand enter into the luminous body on the other side. Consequently, in theneighborhood of the spacers, reflection electrons are intercepted by thespacers, and the diminishment of the intensity of halation is caused.Consequently, in the case where the correction processing similar tothat to the pixels located not in the neighborhood of the spacers isperformed to the pixels in the neighborhood of the spacers, thecorrection processing rather brings about overcorrection to the pixelsin the neighborhood of the spacers. Accordingly, the second embodimentis configured differently from the first embodiment to alter thecoefficients a11 to a55 in the neighborhood of the spacers, and to makesit possible to alter the values of the coefficients a11 to a55 in theneighborhood data integrators 20.

That is to say, as shown in FIG. 7, it is supposed similarly in thedescription of the first embodiment that the pixels in the area to beprocessed by the neighborhood data integrator 20 are p11 to p55. Thecoefficients a11 to a55 shown in FIG. 4 are the coefficients by whichthe pixel data of the pixels p11 to p55 is multiplied. Moreover, it issupposed in the second embodiment that the pixel rows are referred to asfollows in order: the pixel row located over a spacer is referred to as“first over neighboring”, the pixel row located over the first overneighboring is referred to as “second over neighboring”, the pixel rowlocated over the second over neighboring is referred to as “third overneighboring”, and so forth. To put it concretely, for example, as shownin FIG. 7, in the case where the spacer is located at a position A, thefirst over neighboring is the row of the pixels p51 to p55. Moreover,the second over neighboring is the row of the pixels p41 to p45, and thethird over neighboring is the row of the pixels p31 to p35. Furthermore,it is supposed that the pixel rows are referred to as follows in order:the pixel row located under a spacer is referred to as “first underneighboring”, the pixel row located under the first under neighboring isreferred to as “second under neighboring”, the pixel row located underthe second under neighboring is referred to as “third underneighboring”, and so forth. To put it concretely, for example, as shownin FIG. 7, in the case where the spacer is located at a position B, thefirst under neighboring is the row of the pixels p51 to p55. Moreover,it is also supposed in the second embodiment that the verticalresolution of the display apparatus is 768 lines and 20 spacers arearranged with a space of 40 rows in between.

In FIG. 7, in the case where a spacer is located at the position A, thelower limit of the pixels generating reflection electrons irradiatingthe watched pixel p33 is the row of the pixels p51 to p55. Thereflection electrons generated by the rows located at the pixels lowerthan the row of the pixels p51 to p55 do not irradiate the watched pixelp33 independent of the existence of the spacer. Consequently, thereflection electrons radiated to the watched pixel p33 are notintercepted by the spacer. Therefore, in the case where the spacer islocated at the position A, the coefficients a11 to a55 are set to be thevalues shown in FIG. 5B similarly in the first embodiment.

Moreover, in the case where the spacer is located at the position B, thereflection electrons from the pixels located on the opposite side to thewatched pixel p33 with regard to the spacer among the reflectionelectrons to be radiated to the watched pixel p33 are intercepted by thespacer. Moreover, the reflection electrons p51 and p55 are not radiatedto the watched pixel p33 independent of the existence of the spacer. Onthe other hand, the reflection electrons from the pixels p52 to p54 areintercepted by the spacer.

The neighborhood data integrators 20 of the second embodiment areseverally an arithmetic processing unit for calculating an integratedvalue of the drive data of the pixels influencing halation lightemission to the watched pixel p33. Accordingly, it is necessary toexclude the pixel data which does not influencing the halation lightemission owing to the interception of the reflection electrons by aspacer from the integration. Therefore, in the case where the spacer islocated at the position B in FIG. 7, the coefficients a52 to a54 take 0,and the coefficients a11 to a55 take the state of the values as shown inFIG. 8A.

Moreover, also in the case where the spacer is located at a position Cas shown in FIG. 7, the reflection electrons to be radiated to thewatched pixel are intercepted by the spacer. In this case, thereflection electrons of the pixels p41 to p45 and p52 to p54 located onthe opposite side to the watched pixel with regard to the spacer areintercepted by the spacer. The reflection electrons of the pixels p51and p55 are not radiated to the watched pixel p33 independent of theexistence of the spacer. In this case, the coefficients a11 to a55 takethe values shown in FIG. 8B.

In the above, the cases where the watched pixel p33 is located on theupper sides of the spacers have been described. On the other hand, inthe case where a spacer is located at a position D, the watched pixelp33 is located on the lower side of the spacer. In this case, thereflection electrons of the pixels located on the lower side of thewatched pixel p33 are not intercepted by the spacer. Therefore, thecoefficients a31 to a55 on the lower side of the watched pixel p33 takethe values similar to those of the first embodiment.

On the other hand, the reflection electrons of the pixels located on theupper side of the watched pixel p33 are intercepted by the spacer sothat all of the coefficients a11 to a25 take 0. Moreover, in the casewhere the spacer is located at the position D, the coefficients a11 toa55 take the values shown in FIG. 8C. Similarly, in the case where aspacer is located at a position E of FIG. 7, the coefficients a11 to a15of the pixels located on the opposite side to the watched pixel withregard to the spacer take 0, and the other coefficients take the valuessimilar to those in the first embodiment. Consequently, in the casewhere the spacer is located at the position E, the coefficients a11 toa55 take the values shown in FIG. 8D. Moreover, in the case where thespacer is located at the position F, the reflection electrons radiatedto the watched pixel p33 are not intercepted by the spacer again.Therefore, the coefficients in this case take the values shown in FIG.5B similarly in the first embodiment.

Moreover, the switching of the coefficients described above is executedduring a blanking period in a horizontal synchronization period. To putit concretely, for example, in the case where the spacer is located atthe position A in FIG. 7, the values shown in FIG. 5B are set as thecoefficients a11 to a55, respectively. In this case, the pixels p51 top55 is the first over neighboring. That is to say, because the inputdata R1, G1 and B1 are the pixel data of the pixel p55, the input datais the date of the first over neighboring.

Next, in the case where the spacer is located at the position B in FIG.7, the pixels p51 to p55 are the first under neighboring, and the inputdata R1, G1 and B1 are the data of the first under neighboring. In thiscase, the values shown in FIG. 8A are set as the coefficients a11 toa55, respectively. Then, the coefficients a11 to a55 are switched fromthe values shown in FIG. 5B to the values shown in FIG. 8A in theblanking period between the switching of the input data from the data ofthe first over neighboring to the data of the first under neighboring.

Next, in the case where the spacer is located at the position C in FIG.7, the pixels p51 to p55 are the second under neighboring. That is tosay, the input data R1, G1 and B1 are the data of the second underneighboring. In this case, the values shown in FIG. 8B are set as thecoefficients a51 to a55, respectively. Then, the coefficients a51 to a55are switched from the values shown in FIG. 8A to the values shown inFIG. 8B in the blanking period between the switching of the input datafrom the data of the first under neighboring to the data of the secondunder neighboring.

Similarly, the coefficients a11 to a55 are switched from the valuesshown in FIG. 8B to the values shown in FIG. 8C in the blanking periodbetween the switching of the input data from the data of the secondunder neighboring to the data of the third under neighboring. Moreover,the coefficients a11 to a55 are switched from the values shown in FIG.8C to the values shown in FIG. 8D in the blanking period between theswitching of the input data from the data of the third under neighboringto the data of the fourth under neighboring. Moreover, the coefficientsa11 to a55 are switched from the values shown in FIG. 8D to the valuesshown in FIG. 5B in the blanking period between the switching of theinput data from the data of the fourth under neighboring to the data ofthe fifth under neighboring.

As described above, the neighborhood data integrated values R16, G16 andB16 are composed of only the data of the reflection electronsirradiating the watched pixel p33 without including the data for thereflection electrons intercepted by the spacers.

As described above, according to the second embodiment, the effectssimilar to those of the first embodiment can be obtained. Furthermore,in the image display apparatus provided with the spacers such asplate-like members between pixels, it is possible to perform suitablecorrection processing also in the neighborhood of the spacers withoutperforming the correction pertaining to the halation intercepted by thespacers, and to obtain an image display apparatus capable of securing agood luminous characteristic.

Third Embodiment

Next, a correction method according to a third embodiment of the presentinvention is described. In the third embodiment, descriptions are givento an example of giving the data for halation to the data of the pixelsin the neighborhood of the spacers.

Reflection electrons are normally intercepted by the spacers in theneighborhood of the spacers in an image display apparatus. Consequently,the intensity of the halation is diminished than that in the areas notin the neighborhood of the spacers, and luminance shading and colorshading are generated. In the third embodiment, correction processing isnot executed in the areas not in the neighborhood of the spacers, andthe correction processing is executed only to the areas in theneighborhood of the spacers. Thereby, the degrees of the luminance andthe chromaticity of the pixels in the neighborhood of the spacers can bepreserved similarly to the degrees of those of the pixels not in theneighborhood of the spacers.

That is to say, similarly to the second embodiment, the spacers areformed of plate-like members each arranged at the center between acertain pixel row and a row under the pixel row also in the thirdembodiment. Moreover, it is supposed that the vertical resolution of thedisplay apparatus is 768 lines and 20 spacers are arranged with a spaceof 40 rows in between similarly to the second embodiment. On the otherhand, differently from the second embodiment, in the third embodiment,the amounts of the halation intercepted by the spacers are calculated,and the estimation amounts of the intercepted halation are added to thedata of the watched pixel. Thereby, the generation of luminance shadingand color shading is diminished.

In case of the configuration in which the spacers are arranged betweenrows and rows, there is the case where the halation from the pixelslocated on the same row as that of a watched pixel is not intercepted byany of the spacers while the halation from the pixels which are locatedon rows different from that of the watched pixel and are driven at thetiming different from that of the watched pixel is intercepted by thespacers.

Consequently, in the case where the drive data of the watched pixel isdenoted by X and the drive data after the correction of the drive data Xis denoted by X′, the expression (10) in the first embodiment isexpressed as the following expression (20) in the third embodiment.

$\begin{matrix}{X^{\prime} = {X + {k \times C\; 3 \times \frac{{\gamma \;}^{\prime}(0)}{{\gamma^{\prime}(X)}\;}}}} & (20)\end{matrix}$

Hereupon, the reference mark C3 denotes the summation of the drive dataof the pixels which are located in the halation area of the watchedpixel, and the halation of which is intercepted by the spacers.

The principal part of a correction circuit according to the thirdembodiment is shown in FIG. 9, and a neighborhood data integrator isshown in FIG. 10. As shown in FIG. 9, the principal part of thecorrection circuit according to the third embodiment is different fromthose of the first and the second embodiments in that the outputs of theneighborhood data integrators 23 are composed of a couple of pieces ofdata R15 and R16, a couple of pieces of data G15 and G16, and a coupleof pieces of data B15 and B16, respectively. Moreover, the principalpart of the correction circuit according to the third embodiment is alsodifferent from those of the first and the second embodiments in that theadder 7 for processing the data R12, G12 and B12 is not provided and thesign of the output of the coefficient arithmetic operation unit 8 is notinverted at the time of being output. Furthermore, as shown in FIG. 10,the third embodiment is different from the first embodiment in that thecoefficients a31 to a35 shown in FIG. 4, by which the data of the row 22are multiplied, do not exist, and that the adder capable of calculatingthe data R12 is not provided. Because the other configurations of thethird embodiment are similar to those of the first embodiment, theirdescriptions are omitted.

First, the case where the watched pixel does not exist in theneighborhood of the spacers is described. An examination is given to thecase where a spacer exists in the position A or F, or exists on theoutside of the positions A and F in view of the watched pixel p33 inFIG. 7. In other words, the cases are equivalent to the inexistence ofthe watched pixel p33 between the second over neighboring and the secondunder neighboring. In this case, because the reflection electronsradiated to the watched pixel p33 are not intercepted by any of thespacers, luminance shading and color shading are not generated.

In the third embodiment, the neighborhood data integrators 23 calculatedata integrated values of the pixels which emit the reflection electronsirradiating the watched pixel to be intercepted by the spacers. In thiscase, because no pixels are intercepted by the spacers, all of thecoefficients a11 to a25, and a41 to a55 are set to be 0, as shown inFIG. 11A. FIGS. 11A, 11B, 11C, 11D and 11E are views similar to FIGS.8A, 8B, 8C and 8D. In case of the third embodiment, because there arenot the coefficients a31 to a35, their positions are shown as blanks.All of the output data R16, G16 and B16 of the neighborhood dataintegrators 23 of FIG. 9 become 0, and the output data W1 of the adder 6for adding these pieces of data also becomes 0.

Here, in the first and the second embodiments described above, as thecoefficient arithmetic operation unit 8, a coefficient arithmeticoperation unit for multiplying the data W1 by the coefficient k andinverting the sign of the obtained product to output the invertedproduct is used. On the other hand, in the third embodiment, as thecoefficient arithmetic operation unit 8, a coefficient arithmeticoperation unit for multiplying an input signal by the coefficient k andoutput the obtained product without inverting the sign of the product isused. Incidentally, because the input signal W1 is 0 here, the outputdata W3 of the coefficient arithmetic operation unit 8 is also 0.

The output data W3 of the coefficient arithmetic operation unit 8 ismultiplied by the output of the LUT 10R by the multiplier 12R to be theoutput data R18 before being added to the data R15 by the adder 13R. Inthis case, because the data W3 is 0, the data R18 also becomes 0, andthe output data R19 of the adder 13R becomes the same as the data R15.Moreover, similar processing is performed as to G and B, and therespective output data G19 and B19 of the respective adders 13G and 13Bbecome the same as the data G15 and B15, respectively. As the result,the data in the state of receiving no correction processing isdisplayed.

As described above, in case of the state in which the watched pixel isnot located in the neighborhood of the spacers, no correction processingis executed and the input data is displayed as it is in the thirdembodiment.

Next, the case where the watched pixel p33 exists in the neighborhood ofthe spacers is described. As shown in FIG. 7, in the case where a spacerexists at the position B, the reflection electrons of the pixels locatedon the opposite side to the watched pixel p33 with regard to the spaceramong the reflection electrons radiated to the watched pixel p33 areintercepted by the spacer. Consequently, the reflection electrons of thepixels p51 and p55 do not irradiate the watched pixel p33 independent ofthe existence of the spacer. Incidentally, the reflection electrons ofthe pixels p52 to p54 are intercepted by the spacer.

In case of the third embodiment, the neighborhood data integrators 23calculate the data integrated value of the pixels emitting thereflection electrons which are intercepted by the spacer beforeirradiating the watched pixel. Consequently, in the case where thespacer is located at the position B in FIG. 7, the coefficients a52 toa54 become 1 and the other coefficients become 0. The coefficients a11to a25 and a31 to a55 are in the state shown in FIG. 11B.

Then, the outputs of the neighborhood integrators 23 are added to oneanother by the adder 6 to be the output data W1. The output data W1 isan integrated value of the drive data of the pixels from which thehalation is intercepted by the spacer among the pixels driven at thetiming different from that of the watched timing.

That is to say, the data W1 corresponds to the summation data C3 in theexpression (20) described above. Moreover, after the data W1 has beenmade to be proportionality constant times (k times) by the coefficientarithmetic operation unit 8, the data W1 is multiplied by the output ofthe LUT 10R, and then is added to the data R15 by the adder 13R. Theprocessing is similarly executed to G and B. Consequently, the outputsof the adders 13R, 13G and 13B are expressed by the following expression(21).

$\begin{matrix}\left. \begin{matrix}\begin{matrix}{{R\; 19} = {{R\; 15} + {k \times W\; 1 \times \frac{\; {\gamma \; {R^{\prime}(0)}}}{\gamma \; {R^{\prime}\left( {R\; 15} \right)}}}}} \\{{G\; 19} = {{G\; 15} + {k \times W\; 1 \times \frac{\gamma \; {G^{\prime}(0)}}{\gamma \; {G^{\prime}\left( {G\; 15} \right)}}}}}\end{matrix} \\{{B\; 19} = {{B\; 15} + {k \times W\; 1 \times \frac{\gamma \; {B^{\prime}(0)}}{\gamma \; {B^{\prime}\left( {B\; 15} \right)}}}}}\end{matrix} \right\} & (21)\end{matrix}$

According to the expression (21), the correction processingcorresponding to that of the expression (20) is executed. Incidentally,in the third embodiment, the limiters 14 are provided at the subsequentstages of the respective adders 13R, 13G and 13B for limiting theoutputs of the respective adders 13R, 13G and 13B in order not to exceedthe maximum value which the drive data can take.

Moreover, in the case where the spacer is located at the position C inFIG. 7, the reflection electrons which are to irradiate the watchedpixel are intercepted by the spacer. In this case, the reflectionelectrons of the pixels p41 to p45 and p51 to p55 located on theopposite side to the watched pixel with regard to the spacer areintercepted by the spacer. Because the coefficients of the pixelsemitting the reflection electrons which are intercepted by the spacerare 1 in the third embodiment, the coefficients a11 to a25 and a41 toa55 take values as shown in FIG. 1C. In this case, the output data W1 ofthe adder 6 corresponds to the data for the halation which has notirradiated the watched pixel owing to the interception by the spacer.

Moreover, in the case where the spacer is located at the position D inFIG. 7, the pixels emitting the reflection electrons which areintercepted by the spacer are located on the upper side of the spacer.The coefficients a11 to a25 and a41 to a55 take the values as shown inFIG. 11D. Similarly, in the case where a spacer is located at theposition E in FIG. 7, the coefficients a11 to a25 and a41 to a55 takethe values as shown in FIG. 11E. Moreover, the switching of thecoefficients described above is executed during a blanking period in ahorizontal synchronization period. Incidentally, because the switchingoperation is similar to that in the second embodiment, its descriptionis omitted.

As described above, according to the correction method of the thirdembodiment, by performing the correction of the neighborhood of thespacers by giving the data for the halation intercepted by the spacersto the drive data of the watched pixel as the correction data, theluminous shading and the color shading in the neighborhood of thespacers and not in the neighborhood of the spacers can be diminished.

In the above, the embodiments of the present invention have beendescribed concretely. The present invention is not limited to theabove-mentioned embodiments, and various modifications based on thetechnical idea of the present invention can be performed. To put itconcretely, the present invention can be similarly applied to theconfiguration using an ultraviolet ray as an energy ray such as a plasmadisplay.

Moreover, a high definition television apparatus can be configured byusing the image display apparatus described above.

(Television Apparatus)

A television apparatus to which the present invention is applied isdescribed with reference to FIG. 12. FIG. 12 is a block diagram of thetelevision apparatus according to the present invention. The televisionapparatus is provided with a set top box (STB) 501 and an image displayapparatus 502 described with regard to the above embodiments.

The set top box (STB) 501 includes a receiving circuit 503 constitutinga receiving unit, and an I/F unit 504. The receiving circuit 503 iscomposed of a tuner, a decoder and the like. The receiving circuit 503receives television signals such as satellite broadcasting and groundwaves, data broadcasting through networks, and the like, and outputsdecoded image data to the I/F unit 504. The I/F unit 504 converts theimage data into the display format of the image display apparatus 502 tooutput the converted image data to the image display apparatus 502.

The image display apparatus 502 includes a display panel 200, acorrection circuit 505 and a drive circuit 506. The correction circuit505 is a circuit for correction shown in FIGS. 3 and 9. The drivecircuit 506 generates a modulating signal on the basis of the imagesignal output from the correction circuit 505. The modulating signal isapplied to the modulation wiring of the display panel shown in FIG. 13.

Because the display panel includes a plurality of modulation wires, thedrive circuit 506 includes a plurality of modulating signal outputtingunits in order to correspond to each modulation wire. Althoughmodulating signals are output from the respective modulating signaloutputting units to the respective modulation wires, the outputs fromthe respective modulating signal outputting units to the respectivemodulation wires are collectively shown in one line in FIG. 13. Theimage data from the I/F unit 504 is once decoded to RGB signals by theimage signal input unit, and the RGB signals are input into thecorrection circuit.

Incidentally, the receiving circuit 503 and the I/F unit 504 may behoused in a housing separated from the image display apparatus 502 asthe set top box (STB) 501. Alternatively, the receiving circuit 503 andthe I/F unit 504 may be housed in the same housing as that of the imagedisplay apparatus 502.

This application claims priority from Japanese Patent Application Nos.2004-078452 filed Mar. 18, 2004 and 2004-365531 filed Dec. 17, 2004,which are hereby incorporated by reference herein.

1-18. (canceled)
 19. An image display apparatus comprising: a pluralityof pixels including first and second pixels neighboring each other, eachpixel including (a) a device generating energy rays and (b) a luminousbody irradiated with the energy rays to emit light according to anamount of the energy rays so as to display in a gray level; a correctioncircuit for correcting an input data corresponding to the gray level ofthe first pixel on the basis of a correction value, and for outputtingcorrected data by correcting the input data; and a drive circuit fordriving the first pixel according to the corrected data, wherein thecorrection value is obtained by adjusting a value in accordance with anonlinear characteristic between the input data corresponding to thegray level which the first pixel displays and the gray level which thefirst pixel displays, wherein a part of the energy rays generated bydriving the device of the second pixel irradiates the luminous body ofthe first pixel, and wherein the value to be adjusted corresponds to anamount of the part of the energy rays.
 20. The image display apparatusaccording to claim 19, wherein the value to be adjusted is determinedbased on the input data corresponding to a gray level which the secondpixel displays.
 21. The image display apparatus according to claim 19,wherein a gray level corresponding to the corrected data is lower thanthe gray level corresponding to the input data.
 22. The image displayapparatus according to claim 19, wherein the device of the second pixelis driven at a timing different from a timing when the device of thefirst pixel is driven.
 23. The image display apparatus according toclaim 19, wherein the device of the second pixel is driven at the sametiming as that at which the device of the first pixel is driven.
 24. Theimage display apparatus according to claim 19, wherein the plurality ofpixels further includes a third pixel which neighbors the first pixel,and wherein the image display apparatus further comprises a shieldingmember for shielding the luminous body of the first pixel from a part ofthe energy rays generated by driving the device of the third pixel. 25.The image display apparatus according to claim 19, wherein the drivecircuit outputs a modulating signal to drive the device of each of thepixels on the basis of the corrected data.
 26. The image displayapparatus according to claim 19, wherein the energy rays are an electronbeam.
 27. The image display apparatus according to claim 26, wherein thepart of the electron beam, which is generated by driving the device ofthe second pixel, and which irradiates the luminous body of the firstpixel, is an electron beam radiated from the luminous body of the secondpixel.
 28. A television apparatus, comprising: a receiving unit forreceiving television signals; and the image display apparatus accordingto claim 19 displaying an image in accordance with the televisionsignals as the input data.
 29. An image display apparatus comprising: aplurality of pixels including first and second pixels neighboring eachother, each pixel including (a) a device generating energy rays and (b)a luminous body irradiated with the energy rays to emit light accordingto an amount of the energy rays so as to display in a gray level; ashielding member for intercepting a part of the energy rays generated bydriving the device of the second pixel to prevent the part of the energyrays from irradiating the luminous body of the first pixel; a correctioncircuit for correcting an input data corresponding to the gray level ofthe first pixel on the basis of a correction value, and for outputtingcorrected data by correcting the input data; and a drive circuit fordriving the first pixel according to the corrected data, wherein thecorrection value is obtained by adjusting a value in accordance with anonlinear characteristic between the input data corresponding to thegray level which the first pixel displays and the gray level which thefirst pixel displays, and wherein the value to be adjusted correspondsto an amount of the part of the energy rays.
 30. The image displayapparatus according to claim 29, wherein the value to be adjusted isdetermined based on the input data corresponding to a gray level whichthe second pixel displays.
 31. The image display apparatus according toclaim 29, wherein a gray level corresponding to the corrected data ishigher than the gray level corresponding to the input data.
 32. Theimage display apparatus according to claim 29, wherein the device of thesecond pixel is driven at a timing different from a timing when thedevice of the first pixel is driven.
 33. The image display apparatusaccording to claim 29, wherein the device of the second pixel is drivenat the same timing when the device of the first pixel is driven.
 34. Theimage display apparatus according to claim 29, wherein the plurality ofpixels further includes a third pixel which neighbors the first pixel,and wherein the luminous body of the first pixel is irradiated with apart of the energy rays generated by driving the device of the thirdpixel.
 35. The image display apparatus according to claim 29, furthercomprising a drive circuit for outputting a modulating signal to drivethe device of each of the pixels, on the basis of the corrected data.36. The image display apparatus according to claim 29, wherein theenergy rays are an electron beam.
 37. The image display apparatusaccording to claim 36, wherein the part of the electron beam, which isgenerated by driving the device of the second pixel, and which isintercepted by the shielding member to prevent the part of the electronbeam from irradiating the luminous body of the first pixel, is radiatedfrom the luminous body of the second pixel.
 38. A television apparatus,comprising: a receiving unit for receiving television signals; and theimage display apparatus according to claim 29 displaying an image inaccordance with the television signals as the input data.